Defibrillators, ImplantableHeart ArrestDefibrillatorsCardiopulmonary ResuscitationEmergency Medical ServicesEmergency Medical TechniciansOut-of-Hospital Cardiac ArrestElectric CountershockResuscitationAmbulancesVentricular FibrillationDeath, Sudden, CardiacTachycardia, VentricularArrhythmias, CardiacTime FactorsEquipment FailureRetrospective StudiesSurvival AnalysisTreatment OutcomeProspective StudiesMyocytes, CardiacPacemaker, ArtificialCardiac Pacing, ArtificialCardiac Resynchronization TherapyElectrocardiographyElectric InjuriesEquipment SafetyHospitals, TeachingHeart FailureCardiac OutputAnti-Arrhythmia AgentsHospitals, GeneralHospitals, UniversityHeartAmiodaroneDevice RemovalFollow-Up StudiesHospital CostsCardiac Surgical ProceduresEquipment DesignCardiomyopathiesElectrodes, ImplantedEquipment Failure AnalysisHospitals, UrbanNursing Staff, HospitalVentricular Dysfunction, LeftCardiac Resynchronization Therapy DevicesStroke VolumeHeart DiseasesRisk FactorsEconomics, HospitalHospitals, PediatricRisk AssessmentHospitalizationProsthesis ImplantationHospital Bed CapacityHospitals, SpecialSyncopeHospitals, DistrictTachycardiaMyocardial InfarctionHeart VentriclesCardiac ElectrophysiologyVolunteersLength of StayElectrophysiologic Techniques, CardiacSurvival RateHospitals, PrivateCardiomyopathy, DilatedFinancial Management, HospitalCardiography, ImpedanceEmergency Service, HospitalBrugada SyndromeEmergency TreatmentCardiac CatheterizationAtrial FibrillationHospital PlanningMyocardiumHospital ChargesDeath, SuddenIncidenceUnited StatesEchocardiographyCardiac TamponadeHeart RateCardiomegalyHospital DepartmentsHeart Conduction SystemMyocardial IschemiaFirst AidElectrocardiography, AmbulatoryHospitals, PsychiatricVentricular Function, LeftTachycardia, SupraventricularCost-Benefit AnalysisHospital RecordsHospital UnitsCardiac Output, LowRegistriesBurns, Electric